1. Technical Field of the Invention
This invention relates to treated substrates containing sanitizer release polymer compositions and, more particularly, to a sanitizing towel treated with an enhanced sanitizer release polymer composition for releasing cationic sanitizers.
2. Description of Related Art
In order to control microbial growth on a surface, a sanitizing solution containing antimicrobials such as sanitizers is applied to the surface with a substrate such as a woven or nonwoven fabric. A sanitizer is a compound that reduces microbial contaminants to safe levels as determined by government Public Health requirements. Currently, the safe level is a 99.999% reduction in the bacterial count.
For the process to be effective, the sanitizing solution must maintain a certain concentration of sanitizer. A serious problem occurs when the woven or nonwoven fabric reduces the concentration of sanitizer in the sanitizing solution. For example, a nonwoven fabric is repeatedly rinsed in a sanitizing solution contained in a bucket, while sanitizing the tabletop surfaces of a restaurant. If the nonwoven fabric is diluting or reducing the effectiveness of the sanitizer in the sanitizing solution, then the tabletop surfaces are not being disinfected. This can lead to an outbreak of pathogenic enteric bacteria, such as nearly all members of the genus Salmonella or E. coli. Pathogenic enteric bacteria can cause illness, or worse death.
In the field of sanitizers, guidelines exist for the minimum concentration of sanitizer in a sanitizing solution to avoid outbreaks of pathogenic enteric bacteria. The two most common sanitizers in sanitizing solutions are quaternary ammonium compound (QAC)-based or chlorine-based sanitizers. For example, by law, QAC-based sanitizer sanitizing solutions must maintain a concentration level of 200-400 parts per million to achieve the 99.999% reduction in the bacterial count.
Structurally, QACs contain four carbon atoms linked directly to one nitrogen atom through covalent bonds and four alkyl groups. The portion attached to the nitrogen atom by an electrovalent bond may be any anion, but it is usually chloride or bromide to form the salt. The nitrogen atom with the attached alkyl groups forms the positively charged cation portion. Depending on the nature of the R groups, the anion and the number of quaternary nitrogen atoms present, the antimicrobial quaternary ammonium compounds may be classified as monoalkyltrimethyl, monoalkyldimethylbenzyl, heteroaromatic, polysubstituted quaternary, bis-quaternary, or polymeric quaternary ammonium compounds.
A QAC is an ion, that is, a molecule that carries an electric charge. More specifically, a QAC is a cation, that is, an ion that possesses a positive charge. A nonionic molecule is an ion that possesses a neutral charge. An anion is an ion that possesses a negative charge. The charge of a molecule affects that molecule""s intermolecular interactions. For example, a cation is attracted to an anion, and a cation repels another cation.
When QACs are applied directly to surfaces, their effect is not long-lasting due to leaching of the compound from the surface. Therefore, frequent applications may be needed to achieve prolonged antimicrobial effects.
The existing woven and nonwoven fabrics used in conjunction with sanitizing solutions to sanitize and disinfect surfaces reduce the concentration of sanitizer in the sanitizing solution rendering the sanitizing solution ineffective. Over a short period of time and under normal use, the existing fabrics reduce the concentration of sanitizer in the sanitizing solution to less than 200 parts per million. The surfaces of woven fabrics are treated with a surfactant to achieve the surface quality desired. A sufactant is a chemical additive that changes the surface attraction between two liquids, or between a liquid and a solid, by changing the surface energy of one or both components. Woven fabrics in common use today with sanitizing solutions are made with anionic surfactants. Nonwoven fabrics are constructed of loose strands of material that are bound together with binders. A binder is an adhesive, applied with a solvent or by melting a softenable plastic, to bond fibers together in a web or one web to another. Nonwoven fabrics in common use today with sanitizing solutions are made with anionic binders and surfactants.
The negative charge of the anionic binders and surfactants utilized in substrates today attracts and bonds the cationic QAC-based sanitizer to the fabric thereby reducing and neutralizing the concentration of sanitizer in the sanitizing solution. Moreover, woven fabrics comprise many interwoven strands of material, thereby creating a large irregular surface area that captures a large number of cationic QACs during use, thereby reducing the concentration of sanitizer in the sanitizing solution. Existing methods to solve this problem are to regularly replace the sanitizing solution or regularly replenish the concentration of sanitizer. However, these existing methods are not without limitations and disadvantages.
These existing methods are time consuming and expensive. Regularly monitoring and replacing or replenishing the sanitizing solution involves considerable employee time and the expense associated with replacing or replenishing the sanitizing solution. Additionally, during busy times in many restaurants, replacement or replenishment of the sanitizing solution is often forgotten, resulting in insufficient levels of microbial reduction.
Therefore, a need has arisen for a sanitizer release polymer composition that is capable of preventing today""s fabrics from bonding to the sanitizer. Further, a need has arisen for a substrate that does not bond to or neutralize the sanitizer. The present invention provides such a composition and substrate.
In one aspect, the present invention is directed to an article for sanitizing a surface utilizing a sanitizing solution that includes a sanitizer at an effective concentration level. The article includes a substrate that absorbs and holds the sanitizing solution, and a composition covering at least a portion of the substrate. The substrate may be, for example, a woven, nonwoven, or knit fabric, a foam or sponge, or other structure suitable for absorbing and holding a sanitizing solution while wiping off a surface. The substrate has a structure that enables a user to wipe the surface with the substrate, thereby applying the sanitizing solution to the surface. The composition is operable to maintain the concentration level of the sanitizer at the effective level.
In another aspect, the present invention is directed to a sanitizing towel utilized to sanitize one of a plurality of areas in a restaurant utilizing a sanitizing solution that includes a sanitizer at an effective concentration level. The sanitizing towel includes a substrate that absorbs and holds the sanitizing solution, and enables a user to apply the sanitizing solution to the surface. The substrate may be selected from the group consisting of woven fabrics, nonwoven fabrics, knit fabrics, and foams. A sanitizer release polymer composition covers at least a portion of the substrate, and is operable to maintain the concentration level of the sanitizer at the effective level. Preferably, the sanitizer release polymer composition comprises at least one cationic surfactant which, in the preferred embodiment, is present in the sanitizer release polymer composition in an amount of about 1 to about 10 weight percent, based on a total weight of the sanitizer release polymer composition. In an alternative embodiment, the sanitizer release polymer composition comprises at least one nonionic surfactant.
In yet another aspect, the present invention is directed to a method of treating a substrate utilized with a sanitizing solution to maintain a sanitizer in the sanitizing solution at an effective concentration level. The method includes the steps of selecting a substrate, selecting a cationic (or nonionic) surfactant for applying to the substrate, and applying the surfactant to the substrate. The surfactant may be a component in a sanitizer release polymer composition in which the surfactant is present in an amount of about 0.1 to about 99 weight percent, based on a total weight of the sanitizer release polymer composition. The composition may be applied to the substrate by diluting the composition with water or an organic solvent, and applying the diluted composition by dip coating, spray coating, or foam coating.